The present invention relates generally to label applicators, and is particularly concerned with a portable-vacuum applicator that receives pressure-sensitive labels in a relative horizontal plane, alters the orientation of the labels to a relative vertical plane, and then applies the labels to desired articles by positive air pressure
The terms "horizontal" and "vertical" are used herein to describe planes that are substantially mutually perpendicular to one another. The use of these terms is soley for the purpose of convenience and is not intended to limit the scope of the invention.
Various types of devices that employ positive or negative air pressure, or both, have been proposed for use in applying adhesive-backed labels to cartons, bottles, and similar articles. One such device, employing both positive and negative pressure, consists of a housing having one wall formed with openings or perforations. A system of parallel, spaced-apart endless belts for transporting the labels is coupled to the housing such that the belts pass along the outside of the perforated wall. The housing is substantially sealed except for the perforated wall and is partially evacuated by means of a suitable vacuum source such as a vacuum pump. The negative pressure within the housing draws air in through the openings of the wall, causing labels to be retained on the belts as the belts are driven past the perforated wall. To apply the labels to an article, intermittent bursts of compressed air, sufficient to overcome the label-retaining force of the vacuum, are applied to the labels through selected openings of the perforated wall, thereby blowing the labels onto the article
In another arrangement, labels to be applied to an article are carried along a straight path by a perforated endless belt. A vacuum is applied behind the perforated belt in order to hold the labels on the belt as they are transported from a label receiving station to a label applying station. At the label applying station, a vacuum/blower system reverses the air flow through the perforated belt in order to blow other labels onto the articles.
Oftentimes in the label application field, pressure-sensitive labels, once they have been printed, are dispensed from a label printer in a plane which has a generally horizontal orientation. The labels may be presented to a label applying device, such as one of the above-mentioned applicators, for application to an article. In both of the aforementioned label applying devices, however, the labels are presented to and blown from the label applicator substantially in the same plane. That plane is the same in which the label is dispensed, typically a horizontal plane.
The applicator does not change the orientation of the label from this original horizontal plane. Consequently, the surface of the article to which the label is to be applied must be aligned in a horizontal plane that is parallel to the plane in which the label is dispensed in order to insure proper application of the labels to the article. This would typically article. require conveying the article beneath the label applying device. The particular shape of the article, however, may make it difficult to convey the article beneath the label applying device. For example, often the surface of the article to which a label is to be applied must be arranged in a vertical plane rather than in a horizontal plane due to the article's shape. In such a case, the aforementioned label applying devices could not be used for applying the labels to the article. Instead, it becomes necessary to manually remove the labels from the printer and directly apply them to the article This process, however, can prove to be cumbersome and time consuming.